Burndown determination??

2003VIPERER

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Oct 31, 2006
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243
Age
49
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MARQUETTE MICHIGAN
was out riding the other day and all of a sudden down she went. engine shut right down. thought it was a bad plug. changed the plug and same thing, backfiring and sputtering. got her home and pulled the plug and put my finger on the hole and pulled her over. NOTHING!! i thought wtf. so i looked down the hole with a light and the piston looked fine. so i pulled the power valve out, which by the way was stuck , after some nice tugging and some brake clean she came out. looked in the hole and OMG nice big hole in the side of the piston. now the cylinder looks ok. i felt it with my fingers and the bore was still smooth andyou could still see the cross hatching on the bore. even though there was a lot of carbon buildup i was shocked.
my question is , do you think this burnt down because the power valve was either stuck closed or was not adjusted right. i did clean them at the begining of the year, roughly 1100 miles, and i run amsoil interceptor. by what i can tell i would blame it on the power valve being stuck closed. let me know what you think.
 

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more pictures

here are some more picturs of the other two pistons,and the bore
 

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it look more to be a lean burn down for some reason we don't know .why..probably bad gaz again ..look like it seize but u didnt stop ....or maybe u didnt notice fast enough so after the fire goes around the ring its melt really fast..u can see wash on clutch side almost nothing middle and none on the blown piston
 
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modsrx said:
it look more to be a lean burn down for some reason we don't know .why..probably bad gaz again ..look like it seize but u didnt stop ....or maybe u didnt notice fast enough so after the fire goes around the ring its melt really fast..u can see wash on clutch side almost nothing middle and none on the blown piston

i was going to comment on the piston wash too. not enough wash for me to feel safe/comfortable. i would tear the bottom end down too. you know where some of those piston particles went. also, that thing was definetely lean.

is the sled all stock?
 
I can say with all certainty that a stuck PV will not cause a burn down.

It certainly looks lean to me.
 
Most of the lean burn downs I have seen/experienced have been a hole in the top of the piston. When it,s on the side it,s more apt to be detonation from too low octane & i have burned down a few....both ways!!!!
 
YAMAHIZAL700 said:
x2 How bullit proof are they? This year has been terrible for sure!

they are bullet proof motors, but due to the crap gas this year, and the sleds age, and lack of maintenace thru the years, will = burndown.
 
I do a lot of long trail rides. My riding buddies include 2 900 Fusions 05/06,+an 08 800R Renegade, supercharged RX1, 06 600SDI, 800 MXZ HO,...these sleds have all burned down this winter.[suprisingly my buddies trail mod 2000 TCAT has'nt!] The whole group I ride with is now depending on my DCS system. After we fuel up and travel a few miles I do a full throttle run to see how the fuel is. No DCS...we can all ride hard, if the DCS flashes...we take it easy. In our area SHELL Premiun[VTech] consistently has been good. All the other fuel companies are hit/miss.
 
that's a good idea 800vmax4! My Dad's venture has DCS. We haven't had any issues with bad gas, but he can keep an eye out for us with DCS when we're riding.
 
Stephfg said:
that's a good idea 800vmax4! My Dad's venture has DCS. We haven't had any issues with bad gas, but he can keep an eye out for us with DCS when we're riding.
My 02 SRX is "Trail Ported" so it needs good fuel so the DCS light is pretty sensitive. Your Venture probably does'nt need 91+ octane like your SRX so be cautious using it as your "Fuel Tester"
JMO
 
mopar1rules said:
they are bullet proof motors, but due to the crap gas this year, and the sleds age, and lack of maintenace thru the years, will = burndown.


We have had this gas for 15+years.....

I have never seen so many vipers burning down like this year.
 
horkn said:
We have had this gas for 15+years.....

I have never seen so many vipers burning down like this year.
Personally I think there is more"Octane Cheating" going on at the pumps! You can gey away with it with the modern cars but our high output 2 strokes are paying the price!
 
800vmax4 said:
Personally I think there is more"Octane Cheating" going on at the pumps! You can gey away with it with the modern cars but our high output 2 strokes are paying the price!


x2 ;)!
 
Hey Troll, I hope you are not referring to my post.

If so you are wrong.

Please read up about ethanol before making horrible spelling errors and spouting off untruthful statements. You only make yourself look bad.

I have no connection to the ethanol industry, other than that I am informed about it.

You apparently have read enough of my posts, so how about you visit some links I have posted in the past?

FWIW, e10 is being put in many more gas station's tanks that you realize, even up north. Also, just because I do the majority of my sledding up north, does not mean I don't use any 2 strokes down here. Assuming won't do you any good.

Jackson Wi, huh? Seeing that you live here, you should know better.

I am not the only one that says learn to live with e10, snowtech agrees as well.




Anyway, I give the octane cheating theory in this case a X3 from here as well.
 
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